1997 Fiscal Year Final Research Report Summary
Developing Research on Monitoring System of Chemicals Using Bioassay
| Project/Area Number |
07558289
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
環境影響評価(含放射線生物学)
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| Research Institution | Okayama University |
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Principal Investigator |
AOYAMA Isao Research Institute for Bioresources, Okayama Unviversity Professor, 資源生物科学研究所, 教授 (10026239)
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| Co-Investigator(Kenkyū-buntansha) |
RONG Lou Research Institute for Bioresources, Okayama Unviversity Research Associate, 資源生物科学研究所, 助手 (10284093)
OKAMURA Hideo Research Institute for Bioresources, Okayama Unviversity Research Associate, 資源生物科学研究所, 助手 (90253020)
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| Project Period (FY) |
1995 – 1997
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| Keywords | toxic chemicals / bioassay / monitoring / microorganisms / Daphniamagna / lettus / mobility analysis |
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| Research Abstract |
It is now anxious that environmental pollution by toxic chemicals is concerned with survival of ecosystem and human begins. Under these circumastances, It is now needed that new detecting systems of toxic chemicals in environments with rapidity, easiness and low cost will be done. The object of this study is to detect the toxic chemical in water and in sediments and to know the strength of their toxicity.
In this study, microorganisms, Daphnia magna, phytoplankton and yeast and seed of Lettus were used for toxicity testing and relative growth rate, biomass after given time, the length of tag time were evaluated as an end points. Not only 24 hours lethality but also early mobility change of Daphnia were evaluated. The mobility change of Daphnia at early time was newly developed as an end point. This is very sensitive index to know the existence of toxic chemicals in water and this method has a rapidity to detect toxicity. It takes only three hours. We investigated the possibility of moni
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toring system to detect toxic chemicals in real environment using these bioassays. The environmental water which we took and investigated were river water. lake water and their sediments and land fill leachates of industrial wastes. Our newly developed bioassay, the method of early mobility analysis of Daphnia takes only three hours. This could be reduced very much the bioassay time compared from normal method which is recommended by OECD which takes from 24 or 48 hours. The sensitivity of this method is found that it is very sensitive to chemicals. When Daphnia is exposed to chemicals a low concentrations, the mobility of Daphnia is stimulated and when is at high concentrations, mobility is inhibited. We found that it can be used as an endpoint expressed as TOXICITY UNIT.
We took environmental samples (water and sediments) along a river and a lake and performed toxicity testing on them. The seasonal change of toxicity was found and suggested that it reflected the agricultural works. The toxicity of land fill leachate was very strong. Only 3% solution of the leachate was detected to be toxicity for Daphnia mobility tests. Daphnia mobility test and elongation inhibition of lettus seeds were more sensitive than micro organisms. Using these battery tests, we can evaluate the ecotoxicity. Less
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